Minimum Number of Swaps to Make the Binary String Alternating LeetCode solution in C++

1
class Solution {
2
  int minFillPos(string &s, char ch, int current = 0) {
3
    int count = 0;
4
    for (int i = 0; i < s.size(); i += 2) {
5
      if (s[i] != ch) count++;
6
    }
7
    return count;
8
  }
9

10
 public:
11
  int minSwaps(string s) {
12
    int oneCount = count(s.begin(), s.end(), '1');
13
    int zeroCount = count(s.begin(), s.end(), '0');
14
    if (abs(oneCount - zeroCount) > 1) return -1;
15
    if (oneCount > zeroCount) return minFillPos(s, '1');
16
    if (zeroCount > oneCount) return minFillPos(s, '0');
17
    return min(minFillPos(s, '0'), minFillPos(s, '1'));
18
  }
19
};